1. Field of the Invention
The present invention relates generally to a touch panel, and more particularly to a touch panel in which the number of leads is reduced. Moreover, the touch panel is free from the problems of interference and signal interference between the electrodes.
2. Description of the Related Art
In recent years, along with the development of touch panel techniques, various portable electronic devices with display function, such as intelligent mobile phones and tablets, have employed touch panels instead of the traditional mechanical keyboards that occupy much room.
In the existent touch panels, most of the touch panels adopted in the portable electronic devices are capacitive touch panels. An ordinary capacitive touch panel includes a transparent substrate. An indium tin oxide (ITO) layer is disposed on a bottom face of the transparent substrate. The periphery of the bottom face serves as a wiring section. Multiple electrodes are formed on the indium tin oxide (ITO) layer. Multiple leads are disposed on the wiring section and electrically connected to the electrodes respectively. The leads are non-transparent bodies. Therefore, it is necessary for the electronic device manufacturer to spray an ink layer on the periphery of a bottom section of a protection board and dispose an adhesive layer on a top face of the touch panel for adhering the touch panel to the protection board. The ink layer of the bottom face of the protection board corresponds to the wiring section of the touch panel for concealing the leads arranged in the wiring section of the touch panel. The ink layer and the adhesive layer not only lead to increase of manufacturing cost and material cost of the electronic device, but also lead to increase of the total thickness of the electronic device. As a result, the portable electronic device can be hardly slimmed, miniaturized and lightened. The above problems must be solved.
To solve the above problems, in some conventional capacitive touch panels, the transverse electrodes and the longitudinal electrodes are disposed on the same plane and finely wired so as to reduce the total thickness. However, the transverse electrodes and the longitudinal electrodes are so closely arranged as to interfere with each other. Also, the distance between the transverse electrodes and the longitudinal electrodes is so short that short circuit or signal interference between the transverse electrodes and the longitudinal electrodes is likely to take place. According to the above, the conventional touch panel has the following shortcomings:    1. The manufacturing cost of the conventional touch panel is higher.    2. The electrodes of the conventional touch panel are likely to interfere with each other.    3. Signal interference between the electrodes is likely to take place.